LOTUS is an integrated space mission design platform for early mission design. It is a browser-based web application and follows a clear fidelity ladder: Explore (LOTUS performs an extensive trade-space analysis), Assess (LOTUS carries trajectory-driven sizing, margins, and mission closure), then External Refine (LOTUS feeds high-fidelity tools).
The history of LOTUS started in 2025 as a personal tool driven by Afonso's passion for astrodynamics. At the time, it was simply a compilation of scripts for trajectory optimization. Since then, major improvements were performed and a change in philosophy drove a trajectory optimization-based view to an integrated Systems Engineering concept. Today, LOTUS is much more than trajectory optimization. It performs broader early-design workflows involving thermal, launch, communication, and cost analysis, just to mention a few.
Of course, LOTUS could not have been built without the several years of research and development in areas than span Space Systems Engineering. You can find a full list of references used during LOTUS development below. Feel free to explore them and learn more about the concepts that drove the development of LOTUS.
Afonso is a Ph.D. candidate at the California Institute of Technology working in the intersection of experimental mechanics, robotics, and inverse methods for material characterization of space structures under the supervision of Prof. Sergio Pellegrino. His research focuses on developing an universal framework for the multiaxial behavior of ultrathin composite materials used in large space arrays.
Born and raised in Portugal, Afonso obtained his Bachelor's degree in Aerospace Engineering at Instituto Superior Técnico (University of Lisbon) in 2023, followed by a Master's degree in Space Engineering at Caltech in 2024.
He has a long-standing fascination with astrodynamics that began early in his life and he is strongly interested in space mission design, in particular for interplanetary missions. At Caltech, Afonso has served as a Teaching Assistant for the Space Engineering courses that explore the intersection of astrodynamics, optimal control, and mission design. He has collaborated closely with Dr. Stefano Campagnola (mission designer at NASA Jet Propulsion Laboratory) and Prof. Michael Watkins (Caltech Professor and previous director of NASA Jet Propulsion Laboratory) from who he has learned countless lessons and insights.
LOTUS was built with passion and curiosity in developing interplanetary trajectory tools capable of generating and comparing multi-objective mission concepts in a fraction of the time required by traditional tools. Its moto is to enable fast physics-aware iterative design. It was subsequently improved based on experiences, difficulties, and lessons witnessed by undergraduate and graduate-level engineering students at Caltech. For his contributions to teaching at Caltech, Afonso was awarded the 2026 Charles Babcock Memorial Award.
In parallel with his work, he was also the mission designer for the Caltech Space Challenge 2026, where he designed a dual-target mission to a Halley-like comet and Venus with the goal of studying water processes in the inner solar system.